1. Strength and toughness: Most of the working conditions of the mold are very bad, and some of them are often subjected to a large impact load, which causes brittle fracture. In order to prevent sudden brittle fracture of mold parts during work, the mold must have high strength and toughness. The toughness of the mold mainly depends on the carbon content, grain size and structural condition of the material.
2. Depressed fracture performance: In the process of mold work, due to the eternal benefit of wheel response force, it often causes depressed fracture. Its forms include repeated attacks with small energy on fatigue fracture, tensile failure, contact failure, and bending failure. The fatigue fracture performance of the mold mainly depends on its strength, toughness, hardness, and the content of assimilate in the material.
3. High temperature performance: When the working temperature of the mold is higher, the hardness and strength will decrease, causing early wear of the mold or plastic deformation and invalidation. Therefore, the mold material should have a higher anti-tempering stability to ensure that the mold has a higher hardness and strength at the working temperature.
4. Resistance to cold and heat stress: some molds are in the condition of repeated heating and cooling during the working process, which makes the surface of the cavity under tension and pressure to change the stress, causing surface cracks and peeling, increasing the conflict force and hindering plastic deformation , Reducing the dimensional accuracy, resulting in invalid molds. Cold and heat failure is one of the main forms of ineffective hot work molds, and this type of mold should have high resistance to cold and heat failure.
5. Corrosion resistance: When some molds such as plastic molds are working, because there are elements such as chlorine and fluorine in the plastic, they will release strong corrosive gases such as HCI and HF after being heated, which will corrode the surface of the mold cavity and increase the roughness of the surface. Degree, aggravated wear is ineffective.
6. Wear resistance: When the blank is plastically deformed in the mold cavity, it moves and slides along the surface of the cavity, causing a violent conflict between the surface of the cavity and the blank, causing the mold to be ineffective due to wear. Therefore, the wear resistance of the material is one of the very basic and very tight properties of the mold.
Hardness is the main component that affects wear resistance. Under normal circumstances, the higher the hardness of the mold parts, the smaller the amount of wear and the better the wear resistance. In addition, wear resistance is also related to the variety, number, shape, size and distribution of carbides in the material.